1. Technical Field
The present invention relates generally to mobile communication systems and, more particularly, to general packet radio services for delivering data over a circuit switched telephone network.
2. Description of Related Art
A General Packet Radio Service (GPRS) is a non-voice value added service that allows information to be sent and received across a mobile telephone network. It supplements, or rides on top, of today's circuit switched data and short message service networks. The theoretical maximum speed of GPRS includes speeds of up to approximately 171.2 kilobits per second (kbps). This maximum speed is achievable in GPRS systems using all eight timeslots at the same time in a Time Division Multiple Access (TDMA) context.
This speed is about three times as fast as data transmission speeds possible over today's fixed telecommunication networks and ten times as fast as current circuit switched data services on Global System for Mobile Communications (GSM) standard TDMA networks. Thus, GPRS systems are advantageous in that they require less system resources to transmit a fixed amount of data in comparison to using a traditional circuit switched approach. By allowing information to be transmitted more quickly, immediately, and efficiently, across the mobile network, GPRS may well be a relatively less costly mobile data service compared to Short Message Service (SMS) and circuit switched data services.
GPRS also facilitates instant connections in which information can be sent or received immediately as the need arises, subject to radio coverage. No dial up modem connection is necessary. GPRS, similar to some broadband connections for personal computers, often is referred to as being “always connected”. Thus, another one of the advantages of GPRS is that data may be transmitted immediately, whenever the need arises. In contrast to circuit switched data networks in which a connection must be established to transmit a data packet or data file, GPRS operation is extremely efficient in those situations in which a small amount of data is to be sent. As the emphasis of many designs today are to create wireless computer networks, and to connect data devices including personal computers to wireless transceivers and mobile terminals, a system that provides instantaneous response such as GPRS is very important for time critical applications, and, more generally, for the implementation of wireless computer networks. For example, a remote credit card authorization system implemented in a wireless network can be greatly improved if it is unnecessary for the customer to wait the amount of time that is required to establish a connection.
As suggested before, GPRS involves overlaying a packet based air interface on an existing circuit switched wireless network. For example, the circuit switched wireless network may comprise a GSM network. Accordingly, the user is given an option to utilize a packet based data service. In order to overlay a packet based air interface over a circuit switched network, the GPRS standard defines new infrastructure nodes to minimize the impact to existing networks in terms of hardware and software. For example, a gateway GPRS service node (GGSN) and a serving GPRS support node (SGSN) are two such infrastructure nodes.
Another advantage of GPRS is that the packet switching that results from the infrastructure nodes allows the use of GPRS radio resources only when users actually are sending or receiving data. Unlike traditional circuit switched voice networks, a connection is not continuously reserved for a user for the intermittent transmission of data. This efficient use of scarce radio resources means that larger numbers of GPRS users can share the same bandwidth and be served from a single base station or cell. The actual number of users that may use the system at one time depends, of course, on the amount of data being transferred.
GPRS and a similar and newer technology known as the Universal Mobile Telecommunications System (UMTS) use a packet-mode technique to transfer high speed and low speed data and signaling in an efficient manner to optimize network and radio resources. Strict separation between the radio subsystems and network subsystems is maintained thereby allowing a network subsystem to be reused with other radio technologies. A common packet domain core network is used for both GSM and UMTS. The common core network provides packet switch services and supports differing quality of service (QoS) levels to allow efficient transfer of non-continuous bit rate traffic (for example, bursty data transfers).
The UMTS network, also provides connectionless services. Moreover, GPRS and UMTS support push services. A push service is the delivery of data or multimedia information from a network node to user equipment for the purpose of providing subscriber based information from the network. A push service also can include activating a Packet Data Protocol (PDP) context, if necessary. Examples of delivery networks that offer push services include, as stated, the GPRS network, but can also include other equipment, such as a session initiation protocol (SIP) proxy, a push proxy or an SMS service center. Push services are becoming popular because of their ability to deliver advertisements, as well as subscriber ordered content services such as streaming media, web pages, traffic conditions, sports scores, stock quotes, etc. New services and features being offered require that push capabilities be implemented to enable external Internet protocol networks to deliver data to third generation (3G) wireless terminals in the paging system (PS) domain.
Some of these new services and features are provided by content service providers that charge for the content accessed and applications used. Traditionally, Internet usage has been base on time on-line due to the reliance on the original public switched telephone network (PSTN) that maintained a connected switched circuit regardless of the amount of data transiting the switched circuit. Providing content based billing motivates IP network service providers to charge for content delivered to the mobile subscriber and to adjust the charge for data packets that are not delivered. IP network providers, therefore, need a method for content aware accounting for use in subscriber charging.
Another aspect of 3G evolution is the concept of pre-paid service. In some countries it is estimated that 80% of new mobile subscribers are using the pre-paid service option. It is especially important, therefore, that pre-paid subscribers are charged only for content actually delivered. A need exists, therefore, for a method of creating content aware accounting when delivering content based packets to mobile users. Moreover, many IP network operators are entering into partnership agreements with the content service providers in order to access the revenue stream generated by content based services. Accordingly, accurate content aware accounting is needed to divide the revenue stream. There is a need, therefore, for a system and method that supports content delivery while also providing accurate charging records based on the actual content delivered.